high pitched whistle under load

[Cracka Matt]

ok, now i have a new problem and will do my best to describe it. engine is an r32 rb20. under load, usually around 3-4000 rpm I get this high pitched whistle/noise. it starts off low pitched but rev it abit higher and it gets..higher pitched..yeah. cant seem to figure out what it is. fresh oil change, checked all the couplers for the front mount intercooler piping. checked as many places i could for some sort of leak that would give me an indication of why its doing this. also the exhaust sounds abit different like there is a leak somewhere, sounds more like an old truck now and every now and then when shifting or rpm drops i get a pop out of the exhaust, usually abit of fire. it tends to want to just die on me as well. starts fine but from time to time if i dont hit the accelerator pedal, the rpms will just drop until it dies. any ideas? here are a list of my mods incase something might be related. here are a couple videos of the sounds if that will help more.

http://s25.photobucket.com/alb...3.flv

http://s25.photobucket.com/alb...2.flv

ARP Head Studs,GReddy 1.2mm Head Gasket,GReddy Timing belt,Fidanza adjustable cam gears,Hybrid FMIC and piping,Turbo XS BOV,HKS pod filter,3" exhaust with Fujitsubo NGK axle backGTR fuel pumpKoyo radiator w/ dual 12" fans,GReddy EManage,GReddy Profec E-01,GReddy Auto Timer,HKS Hypermax D coilovers,front camber plates,Cusco front strut bar,Cusco front tension rods,

[Carl H]

thats a belt squeeling...check you belt tensions as well as timing belt tension.

[Cracka Matt]

thought of that as well but the belt tensions are within specs, hell i even removed the alternator belt to make sure the bearings inside the alt werent going out.

[Coolwhip]

check your turbo elbow gaskets, especially the one between the turbo and the pipe itself. It might be leaking, and/or you might be experiencing a turbo going bad.

[Cjmartz2k]

Sounds like some kind of bearing going bad. If it's not the alt. then maybe it's the water pump, a/c, or something like that. Doesn't sound like a belt to me. I would think that would be more of a loud squeal that's not quiet so linear.

[Carl H]

could be timing belt bearings...

[Coolwhip]

from the sound of these replies its scary!

...tick...tick...tick

[RB26needaparachute]

Maybe its twin charged or something.Sounds like a supercharger to me!!I have no clue what that noise is..sry!

[Cracka Matt]

checking the gaskets today to see whats going on. gonna take a drive before so and see if its having trouble making or holding boost before i start on anything, as i only drove it a small distance when i heard the noise and then parked it to be safe. it only seemed to be making the noise at rpms higher than 3,000. thanks for all the replies btw. the army is holding alot of my free time hostage so having people point me in some directions helps.

[rb25drag]

Maybe its twin charged or something.Sounds like a supercharger to me!!I have no clue what that noise is..sry!

HAHA I Agree it does sound like a supercharger whining LOL!!

Check you BOV and make sure its not stuck open.

Also try taking your power steering belt off and running the motor like that. Almost sounds like a dry pump.

Thats really all I can think of.

The throttle response on your Rev seemed a little sluggish IMO. So Could be a boost leak somewere's.

[oneslow240se]

It actually sounds like the h22 swap i did. turned out to be the timing belt was too tight which made it sound like a supercharger... other then that

[gawdzilla]

take off your accessory belts individually and see if its still there. if it is, my guess is the timing belt is too tight or either the tensioner/idler pulleys are going bad

[Cracka Matt]

turns out its a gasket in the exhaust system, just a small area which is causing the whistle noise and choppy exhuast note. but thanks guys for all the help!

[Coolwhip]

yay I won!

[Cracka Matt]

well I finally got to work on it for more than 5 minutes today. it turns out it was two issues. one was a gasket as mentioned before, but the other was...



usually id be upset by a broken turbo, but ive been needing an excuse to put on the t3 ive had sitting around. oh well.

[Coolwhip]

Was there a hesitation in higher rpm such as 5-6k rpm?

And where did you get your gaskets from for the elbow?

[Cracka Matt]

as for the hesitation, once i noticed the noise, i never went above the rpm that caused it to start whistling. paranoid i suppose. and the gasket for the elbow, hmm, I cannot seem to remember right off, havent had an issue with that gasket before so its been awhile since i needed one. i think the last one i needed i gave mckinneys a call and they happened to have one but I could be wrong

[Shocker]

Yeah get the t3 on there, thats too bad!

[Cracka Matt]

the t3 is mounted, had to clock it alittle bit but no big deal there, gotta finish welding up the new downpipe, but its christmas and not doing it today. at work tommorow ill make the banjo to an fitting conversion piece(not paying for one off ebay etc when i can make one at work.) and everything will be good.

[Acecool]

Sounds like the turbo...

EDIT: 3500 is usually max boost on the stocker, and if thats where it is hitting it is most likely the turbo...

[Cracka Matt]

uh yeah read some posts up and ive already discovered what the issue is. see pictures. chipped fins on wheel. already installing the new turbo. but thanks anyways, lol

[rb25drag]

Wat is the numbers off the stock Turbo?

[Cracka Matt]

the numbers? meaning the actual number off the turbo casting? trying to identify a turbo?

only numbers on there besides nissan motors brand was 16v on cold side, v163 and 04U on hotside.

[rb25drag]

Ya im trying to Identify my turbo. Ill look at mine tonight and see what it says on it. Thanks!

[Cracka Matt]

not a prob

[skrappy]

The RB20's and 25's come with a small T25 stock.

[BoostFab]

The RB20's and 25's come with a small T25 stock.

wrong!!!!!!!!it's a t28 with a t3 foot print on the turbine side. the sr has the t25.

some rb turbos are ball bearing, so if your turbo bearing is bad, you're screwed in planning dish out some $ for a rebuild. but a leaky rear oil seal probably an easy fix w/ a t28 rebuild kit. becareful disassembling the turbo, the ceramci wheels can break easily.

[Cracka Matt]

eh the broken t25 is now just a paperweight for the moment. have no plans on dealing with ceramic wheels again. second one in two different cars that have broken on me, but not because of overboosting, etc. just ****ty luck

[Cracka Matt]

now that we've hopefully established that I know its the turbo causing the issue, and im in the process of replacing with a t3 unit ive been working on. did alittle welding and made an elbow. keep in mind im no pro welder, and ive only been "rod" welding for a couple weeks now, but heres what i got. Ill be cleaning that up some more just wanted to get a few pics of in its raw form.

[Mistaken]

Not to bad of a weld considering your welding cast iron. Tig welding cast iron is a pain. Were you using ox-acetaline?